1. Field of Invention
This invention relates to a navigation system and memory medium that improve the varieties and efficiencies of searches for a register point within an area such as a vicinity search, an area designated search and so on.
2. Description of Related Art
FIG. 14 is a diagram describing a prior known vicinity search process. When starting the vicinity search process, objects existing within a predetermined limit are searched. The search is executed by searching for register point data (object data) by each area block within the predetermined limit. Further, a hotel may be selected, for example, as a category (genre) to be searched. Hotels are then sorted from the searched register point data and displayed as a list according to their distance from a common origin. Of course, a list can also be displayed by sorting distances only without selecting a category.
FIG. 15 is a diagram describing a search process for displaying a list of categories by designating areas. By selecting areas according to designated categories, for example an administrative unit, then a list of categories common to each area is displayed.
In accordance with a prior known periphery search process, in which a vehicle travels along a specified route guidance, if a stop for meals or shopping is desired, then a user may immediately search for desired facilities by using the navigation system. In such a case, designated categories (genres) that exist within a predetermined limit from a present position (e.g., within 10 km) are displayed in a list. However, if a present position is located near a border between Fukuoka-Prefecture and Yamaguchi-Prefecture, for example, then facilities existing in Fukuoka and facilities existing in Yamaguchi are combined in the list without regard to the types of roads needed to travel to reach the facilities when displayed. Because of this, a user is unable to locate facilities accessible by traveling exclusively on normal roads. Rather, facilities to which the user can go only by traveling on tool roads, i.e., non-normal roads, are also displayed. As a result, a user is likely to select those facilities on non-normal roads by mistake.
Further according to the prior search process, when a category is selected, register point data is displayed in a list only after determining whether each register point data in each area block corresponds to the category selected by the user. This requires a lot of time as all the register point data have to be checked even if the corresponding category does not exist in some area blocks. Moreover, because each area has a fixed list of common categories, a problem arises in that even absent or vacant categories are displayed in a list in some areas.
The invention conducts a search by designating register point data belonging to the same area when making the vicinity search. The invention further conducts a variety of searches when making the vicinity search. Still further, the invention reduces searching time when making the vicinity search and displays a category list by designating an area in a way corresponding to the area.
As described above, according to the invention, because vicinity search data is provided with area data, such as country names etc. of the register points, a vicinity search can be made by specifying objects in the same area, thereby permitting various searches to be made.
Further, when register points are searched by hierarchically limiting categories, the time required for making the vicinity search can be reduced by obtaining information regarding the presence and absence of the register points belonging to category items in the lower hierarchy categories. Further, when searching categories by designating an area, categories with no register point data in the areas are not displayed as only category items with register point data existing are displayed in a list. Thus, the list can be displayed in a way that accurately corresponds to the area.
The navigation system and memory medium of the invention comprises an input means for inputting information to conduct a vicinity search including at least information regarding a reference position of the vicinity search, a display means for displaying a search result, an information storage means for storing at least the vicinity search data and a search means for making the vicinity search on the basis of data input by the input means and stored in the information storage means, wherein the vicinity search data includes at least area information and the search means conducts the vicinity search on the basis of the area information to which register points belong and outputs the search result to the display means. The invention includes area information wherein the area information is country information, district information, prefectural information or municipality information. The navigation system of the invention further comprises an input means for inputting information necessary to conduct the register point search within the area, a display means for displaying the search result, an information storage means for storing data necessary for at least the register point search, a search means for making the register point search within the area on the basis of information input by the input means and data stored on the information storage means, wherein the register point search data within the area include category information to which flags are associated for representing whether register point data are present or absent, and the search means searches for register point data by referring to the flags. The navigation system of the invention further conducts the register point search within the area of the vicinity search and the search means searches for register point data on the basis of information regarding the reference position input by the input means, wherein the register point data is controlled by dividing each vicinity into an area or block, and category information is stored on the basis of each area or block such that a flag representing whether register point data are present or absent as category information of each area or block. Thus, the register point data are controlled on the basis of each category and a flag representing whether the data are present or absent, is given as category information of each area or block, wherein a data structure of category information is hierarchical and flags are given representing whether register point data exist in categories of the lower hierarchy before proceeding to a category of the upper hierarchy. The register point search within an area is the area designated search and the search means searches for register point data on the basis of information regarding an area input by the input means. The area may be a country or an administrative unit, or the like.
The invention further provides a memory medium that stores a program for conducting a vicinity search and for displaying a search result, wherein the conducting of the vicinity search includes searches for area information on the basis of the input reference position for the vicinity search. The memory medium further stores a program for searching for register points within an area on the basis of input data and stored data and for displaying a search result, wherein the step for searching the register points within the area makes a search by referring to flags given to categories in an area that represent whether register point data are present or absent in the area. Further the memory medium of the invention searches for register point data within a predetermined area on the basis of each category and stores a flag representing the existence or absence of register point data based upon either the searched register point data or the category information data for displaying categories.